Relationship between Hematological Parameters and Incidence of Ischemic Heart Diseases among Japanese White‐Collar Male Workers

Relationship between Hematological Parameters and Incidence of Ischemic Heart Diseases among Japanese White‐Collar Male Workers: Toshio Kobayashi, et al. Department of Hygiene and Preventive Medicine, Fukushima Medical University School of Medicine— The determination whether high hematocrit (Hct) and hemoglobin (Hb) are risk factors for ischemic heart diseases (IHD) remains controversial in Japan. To examine whether hematological parameters are independent risk factors for IHD, we conducted a case control study among 3,924 Japanese male white‐collar workers aged 35‐60 yr. IHD cases were defined as men with a first episode of acute myocardial infarction or angina pectoris during the investigation period (from April 1995 to April 2000). Five controls without a history of IHD were assigned for each case, matching for age and smoking status. Twenty‐two IHD cases were developed during the study period and 110 controls were assigned. Hematological parameters, obtained from periodic health examinations undergone before the onset of the disease, were analyzed with the conditional logistic regression model. Multivariate adjusted odds ratios (OR) with 95% confidence interval (95%CI) were estimated, controlling for Body Mass Index, total cholesterol, alcohol use, hypertension and fasting blood sugar. Crude OR (95%CI) for Hct, Hb, red blood cell count (RBC) and Mean corpuscular volume (MCV) were 1.21 (1.03‐1.42), 2.04 (1.17‐3.56), 1.09 (0.96‐1.24) and 1.09 (0.98‐1.22), respectively. The multivariate adjusted OR (95%CI) for Hct, Hb, RBC and MCV were 1.28 (1.06‐1.54), 2.75 (1.39‐5.46), 1.08 (0.92‐1.28) and 1.09 (0.97‐1.24), respectively. These results suggest that Hct and Hb are independent risk factors for ischemic heart diseases among Japanese middle‐aged male white‐collar workers.